III-nitride nanowire LED with strain modified surface active region and method of making thereof
View Patent ↗A light emitting diode (LED) device includes a semiconductor nanowire core, and an In(Al)GaN active region quantum well shell located radially around the semiconductor nanowire core. The active quantum well shell contains indium rich regions having at least 5 atomic percent higher indium content than indium poor regions in the same shell. The active region quantum well shell has a non-uniform surface profile having at least 3 peaks. Each of the at least 3 peaks is separated from an adjacent one of the at least 3 peaks by a valley, and each of the at least 3 peaks extends at least 2 nm in a radial direction away from an adjacent valley.
1. A nanowire device, comprising:
a semiconductor nanowire core; and
a first semiconductor shell located radially around the semiconductor nanowire core,
wherein:
the first semiconductor shell has a non-uniform surface profile having at least 3 peaks;
each of the at least 3 peaks is separated from an adjacent one of the at least 3 peaks by a valley;
each of the at least 3 peaks extends at least 2 nm in a radial direction away from an adjacent valley including a respective indium poor region; and
each of the at least 3 peaks comprises a respective indium rich region having a greater concentration of indium than the indium poor regions of the adjacent valleys.
2. The device of claim 1 , wherein the device comprises a light emitting diode (LED) device and the first semiconductor shell comprises an active region quantum well shell.
3. The device of claim 2 , further comprising a second semiconductor shell located radially outside the first semiconductor shell.
4. A method of making nanowire device, comprising:
forming a semiconductor nanowire core; and
forming a first semiconductor shell located radially around the semiconductor nanowire core,
wherein:
the first semiconductor shell has a non-uniform surface profile having at least 3 peaks;
each of the at least 3 peaks is separated from an adjacent one of the at least 3 peaks by a valley;
each of the at least 3 peaks extends at least 2 nm in a radial direction away from an adjacent valley including a respective indium poor region; and
each of the at least 3 peaks comprises a respective indium rich region having a greater concentration of indium than the indium poor regions of the adjacent valleys.
5. The method of claim 4 , wherein the device comprises a light emitting diode (LED) device and the first semiconductor shell comprises an active region quantum well shell.
6. The method of claim 5 , further comprising forming a second semiconductor shell radially around the first semiconductor shell.
7. The device of claim 1 , wherein the indium rich regions comprises integral portions of an indium gallium nitride active region quantum shell that laterally surround the semiconductor nanowire core.
8. The device of claim 1 , further comprising an underlayer laterally surrounding the nanowire core having a bumpy surface, wherein strain within the first semiconductor shell is locally modified by bumpiness of the bumpy surface.
9. The device of claim 8 , wherein the underlayer has a lesser indium concentration than the indium poor regions.
10. The device of claim 8 , wherein the first semiconductor shell includes a material selected from InGaN and InAlGaN.
11. The device of claim 10 , wherein the indium rich regions contain 15 to 30 atomic percent indium and the indium poor regions contain less than 10 atomic percent indium.
12. The device of claim 3 , wherein:
the semiconductor nanowire core includes an n-doped gallium nitride semiconductor material; and
the second semiconductor shell includes a p-doped gallium nitride semiconductor material.
13. The method of claim 4 , wherein the indium rich regions and the indium poor regions are formed by self-assembly during deposition of the first semiconductor shell.
14. The method of claim 4 , wherein the indium rich regions are formed integrally with the indium poor regions in-situ during formation of an active region shell that includes the first semiconductor shell.
15. The method of claim 4 , wherein the indium rich regions comprises integral portions of an indium gallium nitride active region quantum shell that laterally surround the semiconductor nanowire core.
16. The method of claim 4 , further comprising forming an underlayer laterally surrounding the nanowire core having a bumpy surface around the nanowire core, wherein strain within the first semiconductor shell is locally modified by bumpiness of the bumpy surface.
17. The device of claim 16 , wherein the underlayer has a lesser indium concentration than the indium poor regions.
18. The method of claim 4 , wherein the first semiconductor shell includes a material selected from InGaN and InAlGaN.
19. The method of claim 18 , wherein indium rich regions contain 15 to 30 atomic percent indium and the indium poor regions contain less than 10 atomic percent indium.
20. The method of claim 6 , wherein:
the semiconductor nanowire core includes an n-doped gallium nitride semiconductor material; and
the second semiconductor shell includes a p-doped gallium nitride semiconductor material.